Lifting jack



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1 F. H. SCHWERIN LIFTING JACK Filed May 12. 1922 5 Sheets-Sheet 1 l INVENTOR 1441 ATTORNEY 1552,01 1 F1 FL SIIPVVEFH LIFTING JACK.

F1196 May 1 2 .5 Sheets-Sheet 3' INVENTOIR I TTORNEY Sept. 1, 1925.

I 1,552,011" F. H. SCHWERIN 1.1mm; JACK I Filed May 12. 1922 5 Sheets-Sheet 4 IN VE N TOR A TTORNE V Sept 1, 1925. 1,552,011

- F. H. SCHWERIN LIFTING JACK I and ma 12 1922 5 Sheets-Sheet 5' v. )m 25 y I1 W M 32 36 z I I3 33 I8- jg;

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..J \7 L 2 36 W mvmron WAG/Aw A ATTORNEY Patented Sept. 1, 1925.

UNITED STATES PATENT. OFFICE.

FRANK H. SCI-IWERIN, OF WEST VIEW, IENNSYLVANIA, ASSIGNOR TO THE DUFF MANUFACTURING COMPANY, OF PITTSBURGH, FENNSYLVANIA, A CORPORATION OF. PENNSYLVANIA.

LIFTING JACK.

Application filed May 12, 1922. Serial No. 560,350.

T 0 all whom it may concern:

Be it known that FRANK I-I. SOHWERIN, a citizen of the United States, and aresident of lVest View, in the county of ,Allegheny and State of Pennsylvania, have invented a new and useful Lifting J ack, of which the following is a specification.

The object is to provide an improved screw jack operated by a motor, more particularly by air-drill motors such as are commonly in use in railroad yards and elsewhere where the jack may be employed, the invention not being necessarily limited, however, to the one embodiment herein described. The invention also provides an improvement in worm-gear screw' jacks advantageous in but not limited to motor-operated jacks, since it may also be employed in hand-operated jacks. The invention accordingly comprises the parts,'improvements and combinations herein illustrated and more particularly pointed out in the claims.

In the accompanying drawings forming a part hereof:

Fig. 1 is a side elevation of the jack with the motor, the reversing gearing inside the jack frame being shown in broken lines in the neutral position; i

Fig. 2 is a central vertical section looking in the same direction as Fig. 1, the plane of the-section being indicated by the line 22 of Fig. 3;

Fig. 3 is a top plan, indicating with broken lines the outline of the motor; 7

Fig. 4 is an enlarged sectional elevation of the lower part of the jack, the section being taken on the line 1-4 ofFig. 3

Fig. 5 is an enlarged vertical section on the line 5-5 of Fig. 3; and

Fig. 6 is a fragmentary elevation showing the external starting, stopping and reversing device. e e 1 The jack has a base-frame 1 in the form of a closed shell having an expanded lower portion 2 to rest on the ground and to house parts to be described, and a standard por-,

I thereby the worm, worm-wheel and lifting tion 3.

A lifting member or 'ram 4 is slidably guided in a bearing 5 in the top of the frame and held against rotation by a key 6. In the lower end of the lifting member, .which is hollow, is a nut 7. A. vertical 7 screw 8, constituting a rotary lifting screw member, is r tatably supported .1 the bot tom of the base upon a suitable step-bearing 9 and extends through the nut, with which 1t enacts, upward within the lifting member. The screw members are of self-holding pitch, so as to be capable of sustaining the load at any height to which it maybe raised. Rotation of the screw in one direction raises the lifting member andload, and rotation in the opposite direction lowers them.

, A large-diameter horizontal worm-wheel 10 is fixed asto rotation to the lower portion of the screw, above the bearing 9, and is'meshed by a horizontal worm 11 having shaft or journal portions 12, 13 rotatable in bearings 14, 15 in the ends of a side chamber 16 of the expanded lower portion of the closed base-frame. ,The bearing 15 is afforded by a gland 17 which permits insertion and removal of the worm. Outside 1 of thisgland is an outer chamber 18 formed by an enlargement of the integral chamber structure and by a bolted-on hood 19, the

hood being centered and vertically sustained by a tongue and rabbet joint 20.

Alined bearings 21, :22 in the bottom and top 'of the outer chamber receive a'vertical shaft 23, which is sustained against downward thrust by a collar 24. Loose on the said vertical shaft, within the chamber 18,

with neither gear element, and consequently the jack is not operated though the vertical driving shaft continue to operate. By shiftin-g the clutch member up or down, one

or the other of the 'gears25, 26 is connected to the-shaft and drives the gear 27, and

screw, n one direction or the other, for lifting or lowering, as the case may be.

The reversing clutch member 28 is held and operated by an attendants device com- "the screw. In this way the worm-wheel is;

outer end with a thumb-piece 32, the turnbutton having an eccentric projection which enters 'a circumferentialgroove 34 in the clutch member. A non-positive, springpressed locking plunger 35 (Fig. in the frame snaps into any one of aplurality of positioning recesses 86 (Fig. 5) in the hub of the thum-piece according to the different positions.

The projecting upper end 37 ofthe shaft 23 is formed for engagement with the socket of an air-drill motor 38, a'motor-bottom-rest and power-intake being provided upon which the motor can be simply placed, the attendantnot being required to sustain the weight of the motor. As seen in Fig. 3 this partis offset by virtue of the constructionat such distance from the center or standard of the jack, and sufficiently above though near the bottom, as to accommodate a motor of customary size. The nature of'such motors, being well understood, does not require explanation,

In order to stay the motor laterally, a

top steady-rest 39 is provided, the same comprising an arm having a clamp collar 40 to embrace the standard and a vertical opening in its outer end which is disposed over the motor-bottom-rest to receive the projection' 41 at the topof the motor.

'Upper and lower, substantially circular ribs or bearing surfaces 42, '43 formed, re-' spectively, in the lower body part of' the base frame and in a separate screwed-on bottom meet the opposite faces of the worm- "wheel-1O just inside of its peripheral teeth,

and form with the shell walla circi'imferen- "tia'l lubricant chamber" 44, of which the worm chamber 16 forms part and'enl'argement This chamber can'be filled with grease through an openin closed by a plug 7 45, to lubricate the meshing gear regions, without the necessity of filling the general interior of the shell. tion of these ribs, and particularly of the rib 43, is to aline the worm-wheel 10 with the worm. Much difliculty has been experienced with worm-gear screw acks having the worm-wheel on the. screw, because of the worm-wheel and worm not being in exact relation, causing serious wear and friction resui'lting in derangement -of the jack. According to this part of. the invention I provide an independent alining hearing for the wormwheel substantially as shown, the worm-wheelbemg feathered on the screw, as shown at 47, so that there can be slight relative movement between the screw and wheel in directions parallel with the axis, the feathers nevertheless connecting the worm-wheel in driving relation to relieved of the screw-thrust, and it is a simple matter to form the alining ribsso that they positively and accurately hold the An important funcfeature might also be embodied in screw jacks of specifically different operation. Theouter chamber 18 may likewise be filled with lubricant through an opening closed by a plug 46.

From the foregoing, it will be perceived that a simple, compact and eflicient jack mechanism has been'devised for eration of the kind described.

ower op- I. ll that is" necessary is to put the air-drill motor on the jack and start it running, after which the jack is caused to lift or lower the load by operating the reversing mechanism in the jack by the thumb-piece 32'. The jack can be stopped either by putting the reverse in neutral, or by cutting off the air to the motor. The jack embodies within it areversing gearing, in the chamber 18, and a speed-reducing gearing (the worm and worm-wheel) which cuts the speedof the motor down to a proper speed of operation of the jack, the gearings being interposed inserial relation between the power-intake and the lifting screw.

' lVhi-l'e the form of the invention described is the one preferred and deemed most advantageous, other embodiments are not necessarily excluded, as for example other types of motor might be employed or the motor might even be builtinto the ack. Various details may be altered and there may be re arrangements or'reversals without chan ing the invention.

hat I claim as new is:

1. In a lifting-jack, a" base-frame, aslid able lifting member, a rotary lifting screw member supported in the base-frame, a worm-wheel 'connectedto said screw memher, a horizontal worm and shaft in the lower part of; the base frame meshing said worm wheel, a motor-bottom-rest and vertical power-intake shaft in an offset lower part of thebase-frame, whereon to place a motor, opposed gear members loose on said vertical power-intake shaft,'a clutch member slidably keyed to the shaft adapted for atlernate engagementwith said gear-members and in neutral position to be disengaged from both, an operating device for said clutch member on the outside of the baseframe, and a gear onthe worm shaft in mesh with both said opposed gear members. a 2,111 a lifting-jack, a frame, a rotatable lifting screw, an end-thrust bearing forsaid screw, a worm-wheel on the screw and a driving worm in the frame meshingthe worm wheel, a driving connection between the worm-wheel and the screw which causes these parts to be free of each other in the vertical sense so that the worm-wheel is free of the load thrust, and independent bearing means on the frame positioning the worm-wheel, substantially as set forth.

3. In a lifting-j ack, a frame, an end-thrust bearing therein, a rotatable lifting screw having an enlarged hub resting against said bearing, a. worm-wheel feathered 011 said hub so as to drive the screw while being free thereof in the vertical sense so as to be free of the load thrust, a driving worm in the frame meshing said wormwheel, and circular bearing means on the frame coasting with the outer part of said worm-wheel, substantially as set forth.

4. In a lifting-jack, a hollow frame having an expanded base portion and a' separate bottom fastened thereto, a ram slidable in the stationary frame and containing a nut, a rotatable lifting screw engaging the nut of the ram, a bearing on said bottom for the lower end of the lifting screw, a driving worm in the base portion of theframe, a worm-wheel on the lower portion of the screw meshed by said worm and in driving connection with the screw, but free of the screw in the'vertical sense so as to be free of the load thrust, and circular bearing surfaces on the base portion of the frame and on the separate bottom respectively confining between them the outer portion of the worm-wheel, substantially as set forth.

FRANK H. SGHWERIN. l V 

